Oil pan device

ABSTRACT

An oil pan device (1) is provided with an oil pan (10) that is attached to a lower end (5a) of a crankcase (5) of an engine, and a drain bolt (50). The oil pan (10) includes a recessed portion (33) formed by recessing a bottom surface portion (32) upward, an inclined portion (35) that sections the recessed portion (33), and a bolt hole (36) that is provided in the inclined portion (35), and when the drain bolt (50) is attached to the bolt hole (36), a head portion (52) of the drain bolt (50) is accommodated in the recessed portion (33).

TECHNICAL FIELD

This disclosure relates to an oil pan device and particularly relates tooil pan device used in an engine of a vehicle.

BACKGROUND ART

In an engine of a vehicle, an oil pan for storing engine oil is attachedto a lower end of a crankcase. Generally, a bolt hole for dischargingengine oil is provided in the bottom portion of the oil pan, and a drainbolt for closing the bolt hole is detachably attached to this bolt hole.

CITATION LIST Patent Literature

[Patent Literature 1]: Japanese Unexamined Patent ApplicationPublication No. H5-306653

SUMMARY Technical Problem

In a vehicle, from the viewpoint of improving steering stability and thelike, there is a demand for lowering the mounting position of an engine.On the other hand, in a case where the height position of a bottomportion of an oil pan is lowered, for example, the height position maybe lower than a predetermined lower limit height such as minimum groundclearance of a vehicle, and thus it has been considered to employ a thin(shallow plate) oil pan.

In a case where a thin oil pan is used, the head portion of a drain boltprotrudes downwardly from the lowermost end position of the oil panbottom portion, which is disadvantageous in securing a predeterminedlower limit height. Thus, a method of recessing the bottom portion ofthe oil pan upward to form a recessed portion and uprightly attachingthe drain bolt in the recessed portion is considered.

However, in the method, when engine oil is discharged, a relativelylarge amount of engine oil remains in the oil pan around the bolt hole.

This disclosure is made in consideration of the above circumstances andprovides an oil pan device capable of reducing the amount of oilremaining in an oil pan when engine oil is discharged.

Solution to Problem

An oil pan device according to this disclosure includes an oil pan thatis attached to a lower end of a crankcase of an engine, and a drainbolt, wherein the oil pan includes a recessed portion formed byrecessing a bottom surface portion upward, an inclined portion thatsections the recessed portion, and a bolt hole that is provided in theinclined portion, and when the drain bolt is attached to the bolt hole,a head portion of the drain bolt is accommodated in the recessedportion.

In the oil pan device, a top portion of the recessed portion may bearranged at a position higher than an attachment surface of the oil panwith the crankcase.

In the oil pan device, the recessed portion may be formed in a reversedV shape in a cross-sectional view.

Advantageous Effects

According to the oil pan device of this disclosure, it is possible toreduce the amount of oil remaining in the oil pan when engine oil isdischarged.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a bottom surface side of an oilpan device according to an embodiment of this disclosure.

FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1.

FIG. 3 is a cross-sectional view taken along line of FIG. 1.

FIG. 4A is a view illustrating a level of oil remaining in theembodiment of this disclosure.

FIG. 4B is a view illustrating a level of oil remaining in a case wherea drain bolt is uprightly attached in a recessed portion without aninclined portion.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an oil pan device according to an embodiment of thisdisclosure will be described based on the accompanying drawings. In theembodiment described below, the oil pan device is in a state in whichthe oil pan device is mounted on an engine of a vehicle (notillustrated), and the up-and-down direction is determined based on theup-and-down direction of the vehicle.

FIG. 1 is a schematic view illustrating a bottom surface side of an oilpan device 1 according to an embodiment of this disclosure. FIG. 2 is across-sectional view taken along line II-II of FIG. 1.

In FIG. 2, a reference numeral R indicates a road surface. In FIG. 3, adashed line L indicates the lowermost end position of a head portion 52of a drain bolt 50, and a two-dot chain line X indicates the minimumground clearance of a vehicle. In the embodiment, the engine is arrangedinclined to a cylinder axis so as to be slightly inclined in thevertical direction. Therefore, in FIGS. 2 and 3, in appearance, the oilsurface of engine oil O seems to be inclined to a road surface R in theleft-and-right direction.

In these drawings, the front-and-rear and left-and-right directions ofthe oil pan device 1 are not related with the front-and-rear andleft-and-right directions of a vehicle and are merely determined forconvenience of explanation. In the embodiment, the front direction of anoil pan 10 coincides with the front direction of a vehicle.

As illustrated in FIGS. 1 to 3, the oil pan device 1 includes the oilpan 10 that is attached to a lower end 5 aof a crankcase 5 and a drainbolt 50.

The oil pan 10 is formed of a metal material or a heat resistant resinmaterial and includes a side wall 20 forming a side surface and a bottomplate 30 forming a bottom surface. Inside the oil pan 10, engine oil Ofor lubricating a lubrication target member such as a crank shaft (notillustrated) is stored. In the embodiment, the oil pan 10 is formed of athin (shallow plate) oil pan in which the length of the side wall 20 inthe up-and-down direction is short.

In the upper end portion of the side wall 20, a flange portion 21 whichis attached to the lower end 5 a of the crankcase 5 via a gasket (notillustrated) is provided. The flange portion 21 is detachably attachedto the lower end 5 a of the crankcase 5 by a bolt 22 or the like.

The bottom plate 30 includes a flat plate portion 31 formed in a flatplate shape, and the recessed portion 33 by recessing the bottom surfaceportion 32 (lower surface) upward. This recessed portion 33 is formed ata portion ahead of the left half of the bottom plate 30.

In the embodiment, particularly, the recessed portion 33 has a topportion 33T at a position higher than a position of an attachmentsurface F (the upper surface of the flange portion 21) of the oil pan 10with the crankcase 5 (lower end 5 a). As illustrated in FIG. 3, therecessed portion 33 is formed in a reversed V shape in a cross-sectionalview.

More specifically, the recessed portion 33 is formed by partiallyrecessing the bottom surface portion 32 in a cylindrical shape. Theportion 33 having a recessed partially cylindrical shape has a firstinclined portion 34 formed in a cylindrical circumferential surfaceshape and a second inclined portion 35 formed in a cylindrical endsurface shape. In the embodiment, a bolt hole 36 is vertically providedin the second inclined portion 35.

The bolt hole 36 has a through-hole 36 a passing through the secondinclined portion 35, and a nut portion 36 b arranged in the oil pan 10and coaxially provided with the through-hole 36 a. A flange 36 c isformed at the end portion of the nut portion 36 b on the second inclinedportion 35 side and is fixed to the second included portion 35 bywielding or the like.

In the bolt hole 36, a lateral hole 36 d is formed at the interfacialposition between the nut portion 36 b and the flange 36 c. The lateralhole 36 d is inclined to the axis of the bolt hole 36 and passes throughthe interface substantially horizontally from the lowermost end positionof the through-hole 36 a to the interfacial position.

The drain bolt 50 is detachably attached to the bolt hole 36 from theoutside of the oil pan 10. Specifically, the drain bolt 50 has a screwportion 51 and a head portion 52, and the screw portion 51 is engagedwith the bolt hole 36 by screwing. An O ring 53 for sealing a gapbetween the screw portion and the inner circumferential surface of thethrough-hole 36 a is attached to the root portion of the screw portion51.

The oil pan device 1 of the embodiment is configured such that when thedrain bolt 50 is attached to the bolt hole 36, the head portion 52 isaccommodated in the recessed portion 33. A height position L of thelowermost end of the oil pan device 1 (here, the head portion 52 of thedrain bolt 50) is positioned above a predetermined lower limit height ofa vehicle and in the embodiment, a minimum ground clearance X.

Next, the action effect of the oil pan device 1 of the embodiment willbe described base on FIGS. 3, 4A and 4B. FIG. 4A illustrates a level ofoil remaining when the engine oil O is discharged by detaching the drainbolt 50 from the bolt hole 36 in the oil pan device 1 of the embodimentillustrated in FIG. 3. FIG. 4B illustrates a level of oil remaining in aconfiguration in which a drain bolt is uprightly attached in a recessedportion in an oil pan device 1′ of Comparative Example without aninclined portion.

In the embodiment, as illustrated in FIG. 4A, when the drain bolt 50 isdetached from the bolt hole 36, the engine oil O is discharged to theoutside from the horizontal hole 36 d. Thus, the lower end position (theheight position indicated by the dashed line Z1) of the horizontal hole36 d of the bolt hole 36 is a level of oil remaining.

On the other hand, as illustrated in FIG. 4B, in the oil pan device 1′of Comparative Example, the lower end portion (the height positionindicated by the dashed line Z2) of an opening of a horizontal hole 36d′ of a bolt hole 36′ in the oil pan 10′ is a level of oil remaining. InComparative Example, the level of oil remaining (Z2) is positionedhigher than the level of oil remaining (Z1) of the embodiment.

Accordingly, in the embodiment, by providing the bolt hole 36 in thesecond inclined portion 35, the amount of oil remaining can be reducedby the amount corresponding to (Z2−Z1).

In the embodiment, as illustrated in FIG. 3, the recessed portion 33formed by recessing the bottom surface portion 32 upward is provided andthe head portion 52 of the drain bolt 50 is accommodated in the recessedportion 33. As a result, it is possible to prevent the head portion 52from protruding from the bottom surface portion 32 to the road surface Rside, which is advantageous in lowering the engine mounting position.

The top portion 33T of the recessed portion 33 of the embodiment isarranged oil pan 10 at a position higher than the position of theattachment surface F with the crankcase 5. Therefore, even in a case ofusing a thin oil pan to meet the minimum ground clearance X as a lowerlimit level, a space for accommodating the head portion 52 can besufficiently secured.

In the embodiment, by providing the bolt hole 36 in the second inclinedportion 35, an operation of attachment (detachment) of the drain bolt 50can be easily performed using a longer spanner or wrench to which forceis more easily applicable.

This disclosure is not intended to be limited to the embodimentsdescribed above and may be appropriately modified present disclosurewithin the range not departing from the scope of this disclosure.

For example, in the embodiment, the recessed portion is partiallyrecessed in a cylindrical shape, but the shape of the recessed portionmay have other shapes. For example, the recessed portion may be formedin a substantially hemispherical shape.

The present application is based on the Japanese patent application(JP2015-222131) filed on Nov. 12, 2015, the contents of which areincorporated herein by reference.

INDUSTRIAL APPLICABILITY

According to the oil pan device of this disclosure, it is possible toreduce the amount of oil remaining in an oil pan when engine oil isdischarged.

REFERENCE SIGNS LIST

1: oil pan device

5: crankcase of engine

10: oil pan

32: bottom surface portion

33: recessed portion

35: (second) inclined portion

36: bolt hole

50: drain bolt

52: head portion

1. An oil pan device comprising: an oil pan that is attached to a lowerend of a crankcase of an engine; and a drain bolt, wherein the oil panincludes: a recessed portion formed by recessing upwardly a bottomsurface portion; an inclined portion that sections the recessed portion;and a bolt hole that is provided in the inclined portion, and when thedrain bolt is attached to the bolt hole, a head portion of the drainbolt is accommodated in the recessed portion.
 2. The oil pan deviceaccording to claim 1, wherein a top portion of the recessed portion isarranged at a position higher than an attachment surface of the oil panwith the crankcase.
 3. The oil pan device according to claim 1, whereinthe recessed portion is formed in a reversed V shape in across-sectional view.
 4. The oil pan device according to claim 2,wherein the recessed portion is formed in a reversed V shape in across-sectional view.